For some time, bean sprouts have been widely used in Oriental food preparations and this use is now being enlarged and emphasized in other countries. Bean sprouts are ordinarily grown in a tank of water and are ready to be harvested in about four days. A typical bean sprout includes a bean pod which is encased in a hull and from which the sprout proper extends upwardly. This sprout ordinarily includes some small cut-off roots which must be removed from the sprout after washing the sprout. After cleansing the sprout, the hull must be removed from the bean pod prior to using the sprout.
The present invention is founded on the concept of providing an open-top tank into which water from a suitable source of supply under pressure is delivered. The bean sprouts rise to the surface of the water by flotation and the hulls fall to the bottom of the tank under gravity action. Unsprouted beans also float to the surface and, if not removed, the unsprouted beans rot and spoil the sprouted beans.
Before this application was prepared for filing in the Patent Section of the U.S. Patent and Trademark Office, a patentability search was conducted which brings to light the following patents which are the closest prior art of which the applicants are aware:
U.S. Pat. Nos. 3,998,728, Strauss; 4,063,565, Edwards et al.; 2,238,997, Gaymon; 2,945,589, Olney; 2,365,734, Tromp; 2,362,130, Glenn; 1,835,634, Chapman.
Briefly referring to the disclosures of certain of these patents, it is noted that Edwards et al. is believed to be the reference closest to the subject invention. While it refers to the cleaning of various vegetables, sweet potatoes are particularly mentioned. It operates on the flotation principle and the sweet potatoes are simply dumped in a pile at one end of the flotation tank. The mixture of potatoes and water is driven to an outlet by a paddle wheel. It is lacking in many of the features of the subject invention and particularly in the use of spray nozzles for cleaning the potatoes immediately after they are introduced into the tank, a pair of cylindrical screen members which move the cleaned potatoes to an outlet, and a jet manifold which removes foreign matter from the exterior surface of one of the cylindrical screen members.
Chapman is directed to means for separating good-quality peas from poor-quality ones, which operates under gravity action with the peas being immersed in a brine.
Glenn is another example of grading apparatus for fruits and vegetables by a flotation tank and gravity action.
Olney is still another example of a vegetable separating machine for removing light trash and materials like stones, cinders, broken glass, etc., from good vegetables in a flotation tank.
Gaymon is directed to means for separating dry or frozen fruits from juicy fruits. It is lacking in many of the features of the instant invention.
Strauss is to the separation of raw mineral materials and literally the only point it has in common with the subject invention is the use of a flotation tank.